Since laser devices are enabled to perform processing in a non-contact manner, laser devices are used in various fields, such as processing fields and medical fields. Laser devices are demanded to emit light beams of higher power.
For one of methods for attaining such high power laser devices, there is a method in which laser light beams emitted from a plurality of optical fibers are combined at an optical fiber combiner and then the combined laser light beams are emitted from one optical fiber. Patent Literature 1 below describes an optical fiber combiner usable in such laser devices.
In the optical fiber combiner described in Patent Literature 1, a divergence angle reducing member is provided between a plurality of input optical fibers and a bridge fiber having a tapered portion, in which the divergence angle reducing member emits the light beam emitted from the input optical fiber at an angle of divergence smaller than the angle of divergence of the entered light beam.
One end of the divergence angle reducing member is fusion-spliced to one end of each of the input optical fibers. The other end of the divergence angle reducing member is fusion-spliced to the input end face of the bridge fiber.
[Patent Literature 1] Japanese Patent No. 5216151